The purpose of this research is to synthesize analogues of presqualene pyrophosphate and test them as inhibitors of presqualene pyrophosphate synthetase and squalene synthetase. Initially, the compounds will be tested for inhibition of the conversion of farnesyl pyrophosphate to squalene. This assay is fast, reliable, and involves all reactions of the sequence. If an analogue inhibits this sequence, we will then test it as an inhibitor of squalene synthesis from presqualene pyrophosphate and of the synthesis of presqualene pyrophosphate from farnesyl pyrophosphate. Additional analogues of presqualene pyrophosphate will be synthesized to determine the substrate specificity of squalene synthetase. The molecular structure of the products from enzymatic incubation of the synthetic analogues will be determined.